We can discuss about that, But I will **strongly** fight against this.
This is exactly the reason why I rebuilt nbconvert using template, to avoid profusion of different converter and different export function. 
If we are obliged to do that, then it means that our api and extensibility are crap. 

We can provide a easy way to load sub config if you wish. But using nbconvert with a configuration shipped by Continuum, Matplotlib or Microsoft, or Whatever should not be different than the one shipped with IPython.